Set of key buttons for a handset



FIG. 1 is a front view of a set of key buttons for a handset showing my new design; and,

FIG. 2 is a perspective front view thereof.

The broken line showing the remainder of the handset is directed to environment and is for illustrative purposes only; the broken lines form no part of the claimed design. 

The ornamental design for a set of key buttons for a handset, as shown and described. 